Pre - operative hematological profile: current practice

ABSTRACT

The use of pre-operative laboratory tests became a part of clinical practice in the later half of the 20th century as the clinicians acknowledged identification of pre-operative assessment of prospective postoperative morbidity and mortality. It was, however, argued that routine pre-operative hematological investigations were not cost-effective. Less than 3% of the abnormalities noted were previously unknown, and the number of patients whose surgery was delayed or altered as a result of the abnormal hematological tests ranged from none to 0.5%. In fact, overuse of the laboratory has a detrimental effect on the quality of care because clinicians were over-loaded with irrelevant information. Reference ranges are defined as the central 95% distribution of healthy subjects, and therefore, the probability [p] of an abnormal value occurring in a perfectly healthy patient increases with the number of tests [n] performed [p=1-[.95] n]. Thus, if 12 tests are performed, the probability of at least one test being abnormal is 46% and if 20 tests are performed, at least one will be abnormal in 65% of healthy subjects. Additionally, an abnormal value in an asymptomatic patient is far more likely to be false-positive than in a symptomatic patient, which may result in further unnecessary workup and delay in surgery. The objective of this communication was to analyze current practice in pre-operative hematologic profile evaluation